Heating electric vehicles using a conventional air-conditioning system, in particular at colder places, consumes large amount of the electric power stored in the vehicle's main battery, thus will probably reduce the traveling range of the vehicles. In a vehicle powered by an internal combustion engines, heat produced during the combustion is used to heat other components of the vehicle, such as the passenger's cabin or the driver's seat. This option of using excess thermal energy from the vehicle's motor does not exist in electric vehicles.
Metal-Air electrical cells are known in the art. Such Metal-Air cell or battery includes a metal anode, including for example, aluminum, zinc, lithium, beryllium, calcium, or the like and a gas diffusion cathode. The chemical reaction that produces electricity in the battery is oxidation of the metal anode in the presence of either aqueous or non-aqueous electrolyte. The electrolyte is used for transferring ions between the cathode and anode. In some cases, the electrolyte may also be used for washing away the products of the reaction (i.e., the metal's oxides) which coat the anode, thus allowing the oxidation reaction of the anode to continue and the battery to supply electricity.
Metal-air batteries have potentially high capacity, which make them attractive for use in electric vehicles. However, metal-air batteries known in the art still lack sufficient power to operate as a sole power supplier to electric vehicles.
Conventional batteries used in electric vehicles, for example, lithium based batteries, are large, expensive and have a limited energy source that needs to be recharged regularly, thus limiting the traveling range of the electric vehicles. At optimum driving conditions and without using the electric energy stored in the lithium based battery for any purposes other than driving the car, the maximum traveling range of the Tesla Roadster® was 394 km per charge, using a relatively large and very expensive lithium based battery. Any use of the electricity stored in the battery for heating or cooling the vehicle's passenger cabin, will reduce the traveling range dramatically.
A metal-air battery may be combined with a conventional lithium based battery to extend the traveling range of the electric vehicle when in need (acting like a reserve energy unit). Such a metal-air battery may include a tank for holding a reservoir of electrolyte for circulating the electrolyte in the battery, thereby slowing down the electrolyte's degradation.